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Home , Rubidium chloride

tJaited States Patent (19) (11 3,729,543 Dunn, Jr. (45) Apr. 24, 1973

54 PROCESS FOR PRE-PARNG ALKAL OTHER PUBLICATIONS METAL TETRA-CHELOROFERRATE H. Remy’s “Treatise on Inorg. Chem...," Vol. 2, 1956 (75) Inventor: Wendeli E. Dunn, Jr., Woollahra, Ed., pp. 282 and 283, Elsevier Pub.Co., New York. NSW, Australia J. W. Mellor's "A Comprehensive Treatise on Inorg. and Theoretical Chem...," Vol. 14, 1935, pp. 75, 73 Assignee: Wendel E. Dunn, Inc., Wilmington, 101-103, Longmans, Green & Co., New York. De. C. A. Jacobson’s “Encyclopedia of Chem. Reactions,' 22 Filed: Jan. 21, 1971 Vol. 4, 1951 Ed., page 37, Reinhold Pub. Corp., New York. 21 ) Appl. No.: 108,570 Primary Examiner-Edward Stern Attorney-Samuel V. Abramo (52) tJ.S. C...... 423/138, 423/150, 423/179, 423/208, 423/463 57 ABSTRACT 51 Int. Cl...... C01g 49/10, C01d 3/04, CO 1d 1 1/04 Claimed is a process for producing anhydrous alkali 58) Field of Search...... 23/87 R, 89; metal tetrachloroferrates by heating with distillation a 423/ 138, 150, 179, 208, 463 mixture of an alkali-metal and a hydrous fer ric chloride or an aqueous mixture of an alkali-metal 56 References Cited chloride and ferric chloride. UNITED STATES PATENTS The alkali-metal tetrachloroferrates are useful as in 3,294,482 12/1966 Lerner...... 23/87 RX termediates for producing . 2,928,722 3/1960 Scheller...... 23/87 RX 3,41 1,869 l l fi968 Bradley et al...... 23/87 R 6 Clains, No Drawings 3,729,543 2 PROCESS FOR PREPARNG ALKALE-METAL chloride and alkali-metal chloride are mixed together TETRA-CHLOROFERRATE in approximately equimolar amounts. Preferably equal FIELD OF THE INVENTION moles of the alkali-metal chloride and ferric chloride are reacted, however, some product can be obtained This invention relates to a process for producing al when more of one of the reactants is used. It is con kali-metal tetrachloroferrates. venient to use a slight excess of inexpensive sodium SUMMARY OF THE INVENTION chloride. The excess can be removed from the product by leaching with water as described This invention is directed to a process for producing 10 below and recycled to produce additional product. anhydrous alkali-metal tetrachloroferrates XFeCl4, Sequence of addition of the reactants is not critical, wherein X is an alkali-metal cation comprising heating but in general it is convenient to add the alkali-metal a hydrated ferric chloride or a solution of ferric chloride in solid form to the ferric chloride hydrate or chloride with an alkali-metal chloride and removing solution of ferric chloride. When ferric chloride is used, water by distillation. 15 the application of a small amount of heat is sufficient to Alkali-metal tetrachloroferrates are useful for produce a solution of the ingredients. In this case, the producing chlorine by the Deacon process as described water of hydration serves as the solvent to form the in U. S. Pat. No. 3,376, 112. solution. DESCRIPTION OF THE PREFERRED The reaction is conducted at temperatures of in the EMBODIMENTS 20 range of 40 to about 310. When equal molar amounts The existence of sodium and potassium of hydrous ferric chloride and alkali-metal chloride are tetrachloroferrates by the reaction of anhydrous ferric reacted, it is convenient to gradually heat them to chloride with sodium chloride or , about 40' to 60 where a solution of the reactants in the has been described C. M. Cook, Jr. and W. E. Dunn, 25 water of hydration occurs. This solution is heated to a Jr., J. Phy. Chemo., 65 1505 (1961). The chlorofer temperature where the water boils. The water is rates in anhydrous state provide a convenient chlorine distilled to yield a crude product amounting, in general, containing substances useful as a raw material for the to 90 to 95 percent of the theoretical amount when production of chlorine by the Deacon process as stoichiometric amounts of reactants are used. described in U. S. Pat. No. 3,376, 1 12. 30 The reaction is generally conducted at atmospheric The use of anhydrous ferric chloride to produce pressures, although higher or lower pressures can be chloroferrates is presently uneconomical and incon used, for example, pressures of up to 150 atmospheres venient. In the first place, anhydrous ferric chloride, or higher can be used as well as reduced pressures of cannot be readily prepared from inexpensive hydrous down to 0.1 mm. of Hg or lower. Reduced pressure can ferric chloride. Secondly, it is difficult and expensive to 35 be useful to facilitate the removal of water from the handle hydroscopic material such as anhydrous ferric reaction and to decrease the reaction time. chloride and at the same time maintain anhydrous con It was highly unexpected that the products described ditions. herein could be produced in the presence of water. The I have invented a process for preparing a alkali-metal use of aqueous systems and of hydrated reactants is tetrachloroferrates comprising heating a mixture of an 40 beneficial because it allows the use of more readily alkali-metal chloride such as sodium chloride or potas available hydrous ferric chloride. sium chloride with a hydrous ferric chloride followed The product, which is a liquid at high temperature, by evaporating the water of hydration. It is within the can be used to make chlorine without further purifica scope of my invention to prepare an anhydrous alkali 45 tion. However, unreacted alkali-metal chloride, ferric metal tetrachloroferrates by heating an aqueous mix chloride and can be removed by ture of ferric chloride, an alkali-metal chloride such as leaching the product with water. The product can be sodium chloride or potassium chloride and evaporating dried over a drying agent or by heating with or without the water. It is also within the scope of my invention to a W3C. prepare an anhydrous alkali-metal tetrachloroferrate 50 The procedure can be modified by applying a by reacting an alkali-metal chloride with ferric chloride vacuum to the reaction flask to facilitate the removal of dissolved in hydrochloric acid. water. Reduced pressure down to 0.1 mm. of Hg can be By alkali-metal chloride it is meant , used. sodium chloride, potassium chloride, The following examples further illustrate the inven chloride, and cesium chloride which can be anhydrous 55 tion. or hydrated. By hydrated ferric chloride, it is meant, the compound Fe(Cla-6H2O and any other ferric EXAMPLE 1 containing various waters of hydration. When hydrochloric acid is present, the acid can be Sodium Tetrachloroferrate either concentrated, i.e., 20 percent, by weight, or 60 A mixture of 270.3g. ( 1.0 mole) of ferric chloride dilute, for example, the concentration can be 1.0 hexahydrate and 58.4g. ( 1.0 mole) of sodium chloride molar, 0.1 molar, 0.01 molar, 0.001 molar, or higher or was heated in a flask. The mixture started to melt at lower. 40°C. and was completely melted at 60°C. Boiling took The reaction can be conducted in glass or quartz 65 place at 124°C. and stopped 313°C. equipment. Also equipment made of corrosion re was given off at 300 - 310°C. The residue was cooled sistant metal can be used. Also, a Pyrex glass flask and leached with water. A yield of about 345g. (94%) equipped with a sidearm can be used. The ferric of sodium tetrachloroferrate (NaFeCl) was obtained. 3,729,543 3 4 EXAMPLE 2 metal salts of the tetrachloroferrate anion. The alkali-metal tetrachloroferrates are useful in a Potassium Tetrachloroferrate process for the production of chlorine which is useful The procedure of Example 1 is repeated except that for producing insecticides. For example U. S. Pat. No. 74.55g. ( 1.0 mole) of potassium chloride is used in 3,376, 12 discloses a modification of the well known stead of sodium chloride. The product obtained is an Deacon process for producing chlorine from sodium hydrous potassium tetrachloroferrate (KFeCl4). tetrachloroferrate. All of the alkali-metal tetrachloroferrate disclosed herein can be used in the EXAMPLE 3 modified Deacon process to prepare chlorine. O The foregoing detailed description has been given for Rubidium tetrachloroferrate clarity of understanding only and no unnecessary The procedure of Example 1 is repeated except that limitations are to be understood therefrom. The inven 120.94g. ( 1.0 mole) of rubidium chloride is used in tion is not limited to the exact details shown and stead of sodium chloride. The product obtained is ru described for obvious modifications will occur to those bidium tetrachloroferrate (RufeCl4). 15 skilled in the art. Cesium tetrachloroferrate (CsFeC) is prepared The preferred embodiments in which an exclusive similarly using an equivalent amount of cesium privilege or position is claimed are as follows: chloride instead of the sodium chloride used. 1. A process for producing an anhydrous tetrachloroferrate of the formula EXAMPLE 4 20 XFeCl wherein X is an alkali metal cation, comprising heating Sodium tetrachloroferrate in the temperature range of 40°-60°C., a mixture of ap A solution of 270.3g. ( 1.0 mole) of ferric chloride proximately equal molar amounts of a hydrated ferric hexahydrate, 58.4g. ( 1.0 mole) of sodium-chloride, chloride or an aqueous solution of ferric chloride with and 200 g. of water is heated in a flask. Boiling which 25 an alkali metal chloride and thereafter heating the mix occurred above 100°C. is continued until the tempera ture from boiling up until the temperature of the mix ture of the contents of the flask reached about 3 10C. ture reaches about 310°C., thereby removing the water The residue is cooled and collected. The residue is an present in the mixture by distillation thereafter remov hydrous sodium tetrachloroferrate (NaFeCl4). ing any unreacted components and recovering said al 30 kali metal tetrachloroferrate. EXAMPLE 5 2. The process of claim 1 for producing lithium tetrachloroferrate wherein the alkali metal chloride is Sodium Tetrachloroferrate lithium chloride. A solution of 270.3g. ( 1.0 mole) of ferric chloride 3. The process of claim 1 for producing sodium hexahydrate, 58.4g ( 1.0 mole) of sodium chloride, 35 tetrachloroferrate wherein the alkali metal chloride is 200g. of water and 100g. of concentrated hydrochloric sodium chloride. acid is heated in a flask. The water and acid is removed 4. The process of claim 1 for producing potassium by heating the flask from a temperature of about tetrachloroferrate wherein the alkali metal chloride is 100°C. where distillation of water. occurs. The flask is potassium chloride. heated to a temperature of about 310°C. Sodium 40 5. The process of claim 1 for producing rubidium tetrachloroferrate is obtained in nearly theoretical tetrachloroferrate wherein the alkali metal chloride is amounts. rubidium chloride. The procedures described in Examples 4 and 5 can 6. The process of claim for producing cesium be modified using various amounts of water and tetrachloroferrate wherein the alkali metal chloride is hydrochloric acid. Additionally, the procedures of Ex 45 cesium chloride. amples 4 and 5 can be used to prepare other alkali

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